• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.137-142
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• 2008

Ceramide has emerged as a novel second messenger for intracellular signalling. It is produced from sphingomyelin and is involved in the control of cell differntiation, proliferation, and apoptosis. $C_2$-ceramide, short chain ceramide, plays a role in mediating contraction of cat esophageal smooth muscle cells. We examined the effect of synthesized ceramide analogues on the $C_2$-ceramide and ACh-induced contraction in esophageal smooth muscle cells isolated with collagenase. CY3523, CY3525, or CY3723 inhibited $C_2$-ceramide induced contraction, in a time dependent manne. Each analogue also inhibited the contraction in concentration dependent manners. CY 3523, CY 3525, and CY 3723 had no effect to the contraction induced by PMA. The inhibition with CY3523, CY3525 and CY3723 on the $C_2$-ceramide induced contraction was recovered by PMA. These analogues decreased the density of MAPK bands (p44/42 or p38) in the western blot. These results suggest that ceramide analogues can inhibit $C_2$-ceramide induced contraction via PKC and MAPK dependent pathway.

• 한방안이비인후피부과학회지
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• 제24권1호
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• pp.25-35
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• 2011

Objective : The present study was designed to assess the potential inhibitory activity of an ethanol extract of Belamcandae Rhizoma (EBR) on the alpha-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis signal pathway in B16F10 melanoma cells. Methods : Several experiments were performed in B16F10 melanoma cells. We studied tyrosinase activity, melanin content, cell-free tyrosinase activity and DOPA stain, and performed Western blots and RT-PCR for proteins and mRNA involved in melanogenesis. Results : ${\alpha}$-MSH-induced tyrosinase activity and melanin content were inhibited significantly by EBR. EBR markedly suppressed the protein expression level of tyrosinase in B16F10 melanoma cells. On the other hand, the expression of tyrosinase-related protein-1 (TRP-1) and -2 (TRP-2; DCT) were not affected by EBR. To elucidate the mechanism of the depigmenting property of EBR, we examined the involvement EBR in cAMP response element binding (CREB) protein phosphorylation and microphthalmia-associated transcription factor (MITF) signalling induced by ${\alpha}$-MSH. EBR did not regulate CREB phosphorylation and MITF expression by ${\alpha}$-MSH. Nevertheless, the mRNA expression of tyrosinase was significantly attenuated by EBR treatment without changes in the expression of TRP-1 and -2 mRNA. Conclusion : Our study suggested that EBR inhibits ${\alpha}$-MSH-induced melanogenesis by suppressing tyrosinase mRNA.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7617-7623
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• 2014

Objective: The mechanism of action of fatty acid synthase (FASN) in drug tolerance of breast cancer cells with epithelial-mesenchymal transition (EMT) features was investigated. Methods: The breast cancer cell line MCF-7-MEK5 with stably occurring EMT and tumour necrosis factor-${\alpha}$ (TNF-${\alpha}$) tolerance was used as the experimental model, whereas MCF-7 acted as the control. Tumour cells were implanted into nude mice for in vivo analysis, and cerulenin was used as a FASN inhibitor. RT-PCR, real-time quantitative PCR and Western blot were employed to detect the expression of FASN, TNFR-1, TNFR-2, Wnt-1, ${\beta}$-catenin and cytC at the RNA and protein levels. Results: Compared with MCF-7, TNFR-1 expression in MCF-7-MEK5 was slightly changed, TNFR-2 was decreased, and FASN, Wnt-1, ${\beta}$-catenin and cytC were increased. The expression of Wnt-1 and ${\beta}$-catenin in MCF-7-MEK5 decreased after cerulenin treatment, whereas cytC expression increased. Conclusions: The important function of FASN in the drug tolerance of breast cancer may be due to the following mechanisms: FASN downregulated TNFR-2 expression through lipid rafts to make the cells less sensitive to TNF-${\alpha}$, and simultaneously activated the Wnt-$1/{\beta}$-catenin signalling pathway. Thus, cytC expression increased, which provided cells with anti-apoptotic capacity and induced drug tolerance.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3627-3629
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• 2016

Background: Activation and inactivation of nuclear factor of kappa light chain gene enhancer in B cells (NFKB) is tightly regulated to ensure effective onset and cessation of defensive inflammatory signaling. However, mutations within NFKB, or change in activation and inactivation molecules have been reported in a few cancers. Although oral squamous cell carcinoma is one of the most prevalent forms of cancer in India, with a development associated with malignant transformation of precancerous lesions, the genetic status of NFKB and relative rates of change in oral precancerous lesions remain unknown. Hence in the present study we investigated all twenty four exons of NFKB gene in two precancerous lesions, namely oral submucous fibrosis (OSMF) and oral leukoplakia (OL) to understand its occurrence, incidence and assess its possible contribution to malignant transformation. Materials and Methods: Chromosomal DNA isolated from twenty five each of OSMF and OL tissue biopsy samples were subjected to PCR amplification with intronic primers flanking twenty four exons of the NFKB gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Sequence analysis identified a novel heterozygous mutation, c.419T>A causing substitution of leucine with glutamine at codon 140 (L140Q) in an OL sample. Conclusions: The identification of a substitution mutation L140Q within the DNA binding domain of NFKB in OL suggests that NFKB mutation may be relatively an early event during transformation. To the best of our knowledge, this study is the first to have identified a missense mutation in NFKB in OL.

• 한국발생생물학회지:발생과생식
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• 제3권1호
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• pp.69-74
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• 1999

인슐린 유사 성장 호르몬 1과 2 (IGF-1 & IGF-2)는 착상 전 초기배아 발생을 조절하는 중요한 요소이다. 생쥐 착상 전 초기배아에서 IGF-1의 역할에 관한 연구를 위해, IGF-1과 IGF-1 수용체의 전사물의 존재 여부를 난자와 착상 전 초기배아에서 조사하였다. 새로이 고안된 IGF-1 primer를 이용하여 난자에서 전사물을 검출하였다. 그리고, PCR 산물을 제한효소인 Msp I으로 절단하여 확인하였다. 이 실험에서 IGF-1과 IGF-1 수용체의 전사물이 난자와 착상 전 초기배아에서 모두 검출됨을 보였다. GV-난자에 다량 존재하는 mRNA는 4- 혹은 8-세포기까지 지속적으로 감소하다가 이후에 다시 증가하는 양상을 보였다. GV-난자에서 IGF-1과 IGF-lR 전사물이 존재한다는 것은 초기배아에 존재하는 전사물이 모계유래 산물임을 암시한다. 또한, 난자와 착상 전 초기배아에 IGF-1과 IGF-1 수용체 전사물이 존재하는 것으로 보아 착상 전 초기배아에서 IGF-1은 자가 분비되어 IGF-1 수용체의 신호전달 경로를 통하여 배아발생에 작용하는 것으로 사료된다.

• KSBB Journal
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• 제29권1호
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• pp.50-57
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• 2014

NF-${\kappa}B$ is a transcriptional factor which is involved in many biological processes including immunity, inflammation, and cell survival. Many investigators studied on the mechanism involved in activation of NF-${\kappa}B$ signalling pathway via ubiquitination and degradation of $I{\kappa}B$ regarding skin disease. Some specific molecules including Akt, MEK, p38 MAP Kinase, Stat3, et al. represent convergence points and key regulatory proteins in signaling pathways controlling cellular events such as growth and differentiation, energy homeostasis, and the response to stress and inflammation. Ultraviolet (UV) irradiation has many adverse effects on skin, including inflammation, alteration in the extracellular matrix, cellular senescence, apoptosis and skin cancer. Prunus mume, a naturally derived plant extract, has beneficial biological activities as blood fluidity improvement, anti-fatigue action, antioxidative and free radical scavenging activities, inhibiting the motility of Helicobacter pyolri. Previous reports on various beneficial function prompted us to investigate UVB-induced or other immunostimulated biological marker regarding P. mume extract. P. mume extract suppresses UVB-induced cyclooxygenase-2 (COX-2) expression in mouse skin epidermal JB6 P+ cells. The activation of activator protein-1 and nuclear factor-${\kappa}B$ induced by UVB was dose-dependently inhibited by P. mume extract treatment. This results suggest that P. mume extracts might be used as a potential agents for protection of inflammation or UVB induced skin damage.

• Environmental Analysis Health and Toxicology
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• 제20권1호
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• pp.75-85
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• 2005

This study was aimed to know the effect of cadmium chloride (CdCl₂) on glucose transport in L6 myotube and its action mechanism. CdCl₂ increased the 2-deoxy- (l-3H)-D-glucose (2-DOG) uptake 1.9 and 2.4 fold at 10 and 25 μM respectively. To investigate the stimulating-mechanism of glucose transport induced by CdCl₂, the wortmannin and PD98059 were used as PI3K (phosphatidylinositol 3-kinase) inhibitor and MAPK inhibitor respectively, which did not affect 2-DOG uptake. This fact suggests that CdCl₂ induced 2-DOG uptake may not be concerned to the insulin signalling pathway. Whereas nifedipine, a calcium channel blocker, and trifluoperazine, a calmodulin inhibitor, were found to inhibit the 2-DOG uptake stimulted by CdCl₂. In addition, we also measured the ROS (reactive oxygen species) production and GSH level in L6 myotube to investigate the correlation between the glucose uptake and ROS. CdCl₂(25 μM) increased ROS generation approximately 1.5 fold and changed the cellular GSH level, but GSSG/GSH ratio remained unchanged. CdCl₂ stimulated 2-DOG uptake and ROS generation were inhibited by N-acetylcystein. And BSO pretreatment, a potent inhibitor of γ-GCS, resulted in the dramatic decrease of 2-DOG uptake and also the increase of the sensitivity to cadmium cytotoxicity. The obtained results suggest that CdCl₂-stimulated glucose uptake might be based on the activation of HMP shunt as an antioxidant defense mechanism of the cells.

• Environmental Analysis Health and Toxicology
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• 제20권1호
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• pp.87-95
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• 2005

Cadmium is well known as a toxic metal and has insulin mimicking effects in rat adipose tissue. This study was undertaken to investigate the effect of CdCl₂ on glucose transport and its mechanism in 3T3 - L1 adipocytes. CdCl₂ exhibits respectively 2.2 and 2.8 fold increases in the 2-deoxyglucose uptake when exposed to 10 and 25 μM of CdCl₂ for 12 hr. To investigate the stimulating mechanism of glucose transport induced by CdCl₂. Wortmannin and PD98059 were used respectively as PI3K inhibitor and MAPK inhibitor, which did not affect 2-DOG uptake. This results suggest that induced 2-deoxy-(l-3H)-D-glucose (2-DOG) uptake by CdCl₂ may not be concerned with the insulin signalling pathway. Whereas nifedipine, a calcium channel blocker inhibited the 2- DOG uptake stimulated by CdCl₂. In addition, we also measured the increased production of Reactive oxygen substances (ROS) and glutathione (GSH) level in 3T3-L1 adipocytes to investigate correlation between the glucose uptake and increased production of ROS with H2DCFDA. CdCl₂ increased production of ROS. Induced 2-DOG uptake and increased production of ROS by CdCl₂ were decreased by N-acetylcystein (NAC). And L-buthionine sulfoximine (BSO) a potent inhibitor of γ-GCS, decreased of 2-DOG uptake. Also NAC and BSO changed the cellular GSH level, but GSH/GSSG ratio remained unchanged at 10, 25 μM of CdCl₂.

• 대한약침학회지
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• 제18권2호
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• pp.86-87
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• 2015

Objectives: Condurango is widely used in various systems of complementary and alternative medicine (CAM) against oesophageal and stomach ailments including certain types of cancer. However, until now no systematic study has been conducted to verify its efficacy and dose with proper experimental support. Therefore, we examined if ethanolic extract of Condurango could ameliorate benzo[a]pyrene (BaP)-induced lung cancer in rats in vivo to validate its use as a traditional medicine. Methods: After one month of scheduled BaP feeding (50 mg/kg body-weight), lung cancer developed after four months. BaP-intoxicated rats were then treated with Condurango (0.06 mL) twice daily starting at the end of the four months for an additional one, two and three months, respectively. Effects of Condurango were evaluated by analyzing lung histology, reactive oxygen species (ROS) and antioxidant biomarkers, DNA-fragmentation, RT-PCR (Reverese Transcriptase-Polymerase Chain Reaction), ELISA (Enzyme linked immunosorbent assay) and western blot of several apoptotic signalling markers and comparing the results against those obtained for controls. Results: A histological study revealed gradual progress in lung tissue-repair activity in Condurango-fed cancer-bearing rats, showing gradual tissue recovery after three months of drug administration. Condurango has the capacity to generate ROS, which may contribute to a reduction in anti-oxidative activity and to an induction of oxidative stress-mediated cancer-cell death. Condurango-activated pro-apoptotic genes (Bax, caspase-3, caspase-9, p53, cytochrome-c, apaf-1, ICAD and PARP) and down-regulated antiapoptotic-Bcl-2 expression were noted both at mRNA and protein levels. Studies on caspase-3 activation and PARP cleavage by western blot analysis revealed that Condurango induced apoptosis through a caspase-3-dependent pathway. Conclusions: The anticancer efficacy of an ethanolic extract of Condurango for treating BaP-induced lung cancer in rats lends support for its use in various traditional systems of medicine.

• BMB Reports
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• 제51권12호
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• pp.630-635
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• 2018

C-X-C motif chemokine ligand 2 (CXCL2) is a small secreted protein that exhibits a structure similar to the proangiogenic subgroup of the CXC chemokine family. Recently, accumulating evidence suggests that chemokines play a pivotal role in cancer progression and carcinogenesis. We examined the expression levels of 7 types of $ELR^+$ CXCLs messenger RNA (mRNA) in 264 clinical samples. We found that CXCL2 expression was stably down-regulated in 94% of hepatocellular carcinoma (HCC) specimens compared with paired adjacent normal liver tissues and some HCC cell lines. Moreover, CXCL2 overexpression profoundly attenuated HCC cell proliferation and growth and induced apoptosis in vitro. In animal studies, we found that overexpressing CXCL2 by lentivirus also apparently inhibited the size and weight of subcutaneous tumours in nude mice. Furthermore, we demonstrated that CXCL2 induced HCC cell apoptosis via both nuclear and mitochondrial apoptosis pathways. Our results indicate that CXCL2 negatively regulates the cell cycle in HCC cells via the ERK1/2 signalling pathway. These results provide new insights into HCC and may ultimately lead to the discovery of innovative therapeutic approaches of HCC.